Process of recovering potassium compounds from waste gases of cement-kilns and the like.



H. BLUMENBERG, JR. PROCESS FOR RECOVERING POTASSIUM COMPOUNDS FROM WASTE GASES 0F CEMENT KILNS OR THE LIKE APPUCATION flLEfi MAR IQ. 1915.

1,296,463. Patented M111. -l, lJiJ.

Fig.1.

2/ Inventor: Henv'yfitumqnbergJT. y n d UNITED STATES PATENT OE IOE.

HENRY BLUMENBERG, JR, OF 036 GRANDE, CALIFORNIA.

PROCESS OF REGQVERING POTASSIUM COMPOUNDS FROM WASTE GASES KILNS AND THE LIKE.

Specification of Letters Patent.

To all whom it may concern:

" Be it known that I, HENRY BLUMENBERG, Jr., a citizen of the United States, residlngat Oro Grande, in the county of San Bernar- 15 dino and State of California, have invented "new and useful Improvements in Processes of Recovering Potassium Compounds from Waste Gases of Cement-Kilns and the like,

of which the following is a specification. M My invention relates to a process of recovering potassium ppmpounds carried by 'hot gases and especially gases from a ce- Iiient kiln.

At the present time potassium salts are 15, produced as any product of cement kilns. Feldspar and other potassium containlng materials are used in the manufacture of co- Tment. The high temperature of the cement kilii 'volatilizes the potassium compounds 29 which mixed with cement dust is carried off lby the hot gases.

It is an obJectof the present invention to f pro'vide a process whereby substantially all v the cement dust and approximately one-half 251 01 the potassium compounds are precipitated and the waste gases now practically is; from cement dust, but containing the reinaining portions of the pounds, are subjected to a slmple treatment 8!) whereby the remaining potassium comounds in the gases are. recovered in the Form of substantially pure potassium salts. My invention consists in the steps of the f; hereinafter described and -,claimed.

I In the accompanyingqdrawings which gfoi'm a part of this specification, I have I Figure 1 is a vertical section thereof.

Fig.2 is a top plan view thereof, some poses of. clearer illustration.

45 parts being shown as broken away for pur- 10 indicates'the upper end of a rotary cs ment kiln' which terminates in the lower end of a precipitating tower 11. A conduit 12 i0 conducts the gases from the upper ehd of tower 11 to the lower end of tower 13. A conduit'14 conducts the gases from tower 13 to a centrifugal fan or blower 15 which otassium comforces the same into the lower end of the precipitating tower 16. Another oopduitl? conducts the gases from thenpper end of thetower 16 to the lower end of a tower 18.. 11 is agas "outlet leading from the top of tower 18. l

These towers may be of any suitable height. I have found that tow ers about 25 feet high give excellent results. They are circular in cross section, though they may be of any preferred shape and about 8 feet in diameter. Each tower is provided with a series of perforated. baflie lat'es 19 horizontally arranged. These b evided with perforations 20 o one-halfiiinoh in diameter and about one inch apart. A

ing liquid w i'ch may bewater or an: aqueous mixture of compo md-s s uch asalkaline mire tures containing sodiumepotassiuni, aluminum silicates, or a me tal nitridsolution, or

centrifugal pump 21 circulates ;a .precipi tatcalcium sulfate and the like, suitable for collecting thecement dust and potassium cemv n s a i. .by;- e gases t r a P p 22, leading to the; to of theprecipitating towers 11 and1 3. alved-pipes23 terminati g in spra nozzles 24 in the tops of the tow re 11 an 13 cause the liquidltoatfiow down the towers and through the baffle plates in minute streams.

A lar e ortion of the potassium compounds ,2 and practically all the cement dust. of the-hot gases are precipitated by the liquid and form a magma or slurry which. is collected in the bottoms pithetowers 111and 13.

Outlets 25 lead from the bottomof the towens 11 and 13 to a tank 26 communicating 90 with pipe 27with the centrifugal pump 21.

-A. centrifugal ,pump28 supplies towers 16 i and 18 with afprecipltating iquid by means of pipe 29 and branch pipes-30 terminati'n in spra; nozzles 31 in the tops of said tb ers. Out

32 at the bottom of said towers to a collecthi n1; 331 communicating with pipe 34 with pump 28.. :,-A pipe '35"lead's conducttliefilgigd and precipitated matter from pipe 22 to a filter press 36. 37 is a 100 valve in pipe and 38 is a valve in pipe 22. A valved pipe 39 leads from pipe 29 which latter is provided with a valve 40.

In the operation of-the apparatus, the hot gases coming from the cement kiln pass through the towers 11 and 18 in series and OFK ENT- Patented Mar. 4, 19192- lates are Propractically all of the cement dust is pre cipitated therein. The gases are cooled from a temperature of approximately 120Q F. to about 212 F. and saturated with steam. It should be noted that the centrifugal pum or blower 15 sucks the as through t e towers 11 and 13 and forces them through towers 16 and 18 where the remaining portion of the potassium comounds are precipitated by the water flowln down the towers 16 and 18.

he first two precipitatin towers 11 and 18 precipitate practically al the solid matter carried by the gases anda roxim'ately of the potassium oxid. owever, the percentage of the potassium oxid precipitated in these two towers may vary and deends u on the time factor, that is the ength 0 time during which the gases are passed through the towers.

In the preci itating towers 16 and 18 on the other -si e of the centrifugal blower, the remaining portion of the potassium oxld is precipitated, and I referably use acids such as sulfuric, hy rochloric, boric or nitric acids, forming the corresponding potassium salts, in place of water ordinarily used, which collects otassium compounds in the form of potassium hydroxid and potassiul'n carbonate. It should be remembored that the-hot gases carry large volumes ofcarbon dioxid which in "the presence of moisture, combine'with the potassium oxid to form potassium carbonate. If there are any sulfuroompounds present in the hot ases comin from the cementkiln, which is the case w ere fuel oils containing sulfur compounds are used, such sulfur compounds form sulfuric acid and are precipitated in the first two towers Hand 13, forming potassium sulfate, calcium sulfate and the en The advantage of the present process consists in'the recovery of as high as 50% of potassium compounds carried by the hot of a cement kiln in the form of subtantially pure salts, free from any cement ust I Itighould be noted also that all the calcipmaluminum, magnesium and iron compoiuidsnormally present in the cement dust are caught'and1precipitated in the first two half of the, 65.

towers 11 and 3 and that as high as onetassium compounds are recovered in t e form ofa clear solution, which may be evaporated to dryness in any convenient manner;

I claim:

1. A process of recovering potassium compounds from hot gases carrying the same n ri gigd with other materials in suspension, comprising passing said gases through a preclpitatlng chain er, and causing the same to be contacted with a precipitating liquid whereby substantially all the 'solids carried by the gases and a portion of the potassium compounds are precipitated, forming a slurry, separating the potassium compounds from said slurry, passing the gases from the precipitating chamber into a second precipitating chan'iber, and causing said gases to come in contact with a precipitating so lution, whereby substantiallyall. the re maining portions of the potassium compounds are precipitated in the form of a clear splution.

2. A process of recovering potassium compounds from hot gases carrying the same mixed with other materials in suspension, comprising passing said gases through a prom ituting chamber and causing the same to be contacted with u precipitating liquid 'whereby substantially all the solids carried by the gases and a portion of the potassium compounds are precipitated, forming a slurry, separating the potassium compounds from said slurry, passing the gases from the preciptuting chamber, and causing them to come in contact with an acid capable of combining with potassium to form potassium salts, whereby substantially all the renuiining portions of the potassium compounds are precipitated in the form of a clear potassium salt solution.

3. A process of'recovering potassium compounds from hot gases carrying the same mixed With other materials in suspension, comprising passing said gases through a precipitating chamber and causing the same to be contacted with a precipitating liquid whereby substantially all the solids carried by the gases and a portion of the potassium compounds are precipitated, forming a slurry, se aruting the potassium compounds from sai slurry, causing theguses from the precipitating chamber to come in contact with sulfuric acid, whereby substantial] y all the remaining portions of the potassium compounds are preci itated in the. form of a clear potassium su fate solution.

In testimony whereof I have signed my name to this specification.

HENRY nLUMnNnERo, JR. 

